Urea Casale Sa

Casale Sa

Paolo Brunengo

Federico Zardi

Paolo Sticchi

In an integrated process for urea and melamine production, urea is produced in a urea plant () comprising a high pressure urea synthesis section () from which an aqueous solution comprising urea, ammonium carbamate and ammonia is obtained and a urea recovery section () operating at low pressure, and melamine is produced in a melamine plant () wherein off-gases resulting as by-products of the melamine synthesis are discharged from said plant at a medium pressure and recycled to the high-pressure urea synthesis section ().

Integrated process for urea and melamine production

A process for urea production from ammonia and carbon dioxide, in which part of the aqueous solution comprising urea, ammonium carbamate and ammonia obtained in a urea synthesis section is subjected to dissociation in a treatment section operating at a predetermined medium pressure for the recovery of the ammonium carbamate and of the ammonia contained in it, comprises the steps of subjecting the urea aqueous solution resulting from the aforementioned dissociation step to decomposition in a low pressure urea recovery section and of using at least a part of the condensed steam, obtained by indirect thermal exchange with a second part of said aqueous solution comprising urea, ammonium carbmate and ammonia in a high-pressure stripping unit, as a heating fluid for the dissociation of the first part of the aqueous solution comprising urea, ammonium carbmate and ammonia in the medium-pressure treatment section.

Process for urea production and related plant

A process for urea production from ammonia and carbon dioxide, in which part of the aqueous solution comprising urea, ammonium carbamate and ammonia obtained in a urea synthesis section is subjected to dissociation in a treatment section operating at a predetermined medium pressure for the recovery of the ammonium carbamate and of the ammonia contained in it, comprises the step of subjecting the urea aqueous solution resulting from the aforementioned dissociation step to decomposition in a low pressure urea recovery section.

A method for the removal of nitrogen oxides contained in combustion flue gas through treatment with gaseous ammonia, in which the gaseous ammonia is generated in situ by hydrolysis reaction of an aqueous urea solution (L) whereby the ammonia generated by the hydrolysis (L) is accumulated in gaseous state, under pressure, in an accumulator (A).

Method for the treatment of combustion flue gas

In an integrated process for urea and melamine production, urea is produced in a urea plant () comprising a high pressure urea synthesis section () and a urea recovery section () for separating urea from a carbamate aqueous solution, and melamine is produced in a melamine plant () wherein off-gases resulting as byproducts of the melamine synthesis are discharged therefrom at a pressure of at least 2 bar and recycled to the high pressure urea synthesis section ().

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Lugano, Switzerland

Paolo Brunengo